Furnace-grate.



- J. W. F. MACDONALD.

PURNAGE GR'ATE.

APPLICATION mm) we. 21, 1911.

Patented Mar. 2; 1515;

090 oogoooo I J. W.'F. MAODONALD.

FURNACE GRATB.

APPLICATION FILED AUG. 21, 1911.

Patented Mar. 2, 1915.

2 SHEETS-"SHEET 2 A) W141i THE mmms PETERS go, WASH/Mayor!" n. c.

being adapted to normally lie in substantially horizontal position, as shown in full lines in Fig. 1, to form the fuel supporting surface. One of the other faces is formed with ribs which are adapted to form fuel supporting or clinker and'ash engaging surfaces, only when the grate is moved in the shaking operation, as, for instance, when the sections are turned up into the position indicated in dotted lines, in Fig. 1, which dotted lines indicate the extreme movement in one direction, while the full lines indicate the extreme movement in the opposite direction of the several grate sections.

In grates of this type it has been found that the greatest range of oscillation which can be successfully employed is about 60, and in the present invention it is designed that one extreme of this movement shall leave the flat fuel supporting surfaces of the sections substantially horizontal, and with the rocker bars slightly inclined, the general plane of the inclination to the horizon being about 60. In other words, with a grate section of equilateral triangular form, in which one flat face forms the normal fuel supporting surface, the socket for the reception of the edge of the rocker bar extends substantially parallel with one of the other faces of the section. This arrangement permits of a maximum movement of the grate sections, and the formation of a maximum irregularity during such movement, with a substantially uniform space or opening between the sections. For instance, when the sections are in normal po sition the spaces between them are-substantially the same as the spaces between them .when they are turned to the opposite extreme of their movement, as shown in the dotted lines, Fig. 1, and consequently, there is at no time opportunity for the escape of unburned fuel between the sections and into the ash pit. At the same time the points of the triangles penetrate deeply into the body of the fire, allowing the air to circulate freely to the fuel, so as to give a maximum efficiency andto afford the maximum capacity of the sections for discharging ashes and clinker. Owing to this construction also, the grate sections may be made somewhat shorter than is usual and consequently have a greater leverage or power for breaking up clinker, without unduly increasing the range of movement of the rocker bars and operating connections. Each grate section may be separately re moved from its rocker bar and others substituted for renewal purposes; or, in case the character of fuel used be changed, all of the sections may be changed to suit the particular fuel to be used. At the front and rear of the grate, headers F are provided having the usual transverse projections for supporting the end portions of the body of fuel. The headers at their ends are formed. with hook-shaped projections, adapted to seat in correspondingly shaped seats. or recesses in the ends of the beater bars B and C.

Each of the rocker bars D is provided with a downwardly extending arm D and a connecting bar H serves to connect all of the arms for simultaneous oscillatory movement. Pivotally secured to the connecting bar H is an arm or casting h and to this arm is connected the inner end of link I, which extends through an aperture in the front wall of the furnace, and at its outer end is pivotally connected with the depending portion or arm of the bell crank lever K. In order to allow for the difference in the thickness of the wall of the furnaces, "he connection between the inner end of the link I and arm 72, is made adjustable. For this purpose the arm h is formed with a series of openings h, and the link I with a series of openings 2' which may be brought into registry with the holes in the casting, and the two held together by means of a bolt or other fastening means. In order that there may be a line adjustment over a wide range the holes in the arm are equally spaced, as are the holes in link I, but the distance between the center of the holes in one of these members is not the same as the distance between centers in the other member. As shown in the drawings, there re seven holes in the casting and nine holes in the link, and the distance between, from center to center of every third hole in the casting, is the same the distance from center to center of the fifth hole in the bar. By such an arrangement an adjustment can be made as fine as thedifference between centers of adjacent holes.

The bell crank K is pivotally mounted in a bracket L secured to the front wall of the furnace and is socketed for the reception of a shaking lever or operating handle M. The socket is usually rectangular in cross section so that the handle can only be entered therein when properly positioned with relation to the bell crank, and provision is made whereby the handle or lever cannot be removed from the bell crank unless and until the grate sections have been properly positioned with their fuel supporting faces horizontal and unless and until the said sections are positively locked in such position. To accomplish the aforesaid results, the bell crank K is provided with a pivoted lock 0, having a grate locking projection 0 which is adapted to enter a recess Z in the bracket L for locking the grate in its correct normal position, and a projection or cam 0 for cooperating with a recess m in the shaking lever handle M for locking the latter in its socket in the bell crank, the projections o and 0 being so disposed with relation to each other, that when one is in its operative locking position, the other is in its releasing or unlocking position. That is to say, when the lock 0 is turned to the position shown in Fig. 2, the grate is locked against movement in either direction, and the fuel supporting surfaces of the grate sections are horizontal and in proper position to correctly support the fuel without danger of having the projections on the grate sections burned 05'. In this position the lever or handle may be freely inserted or removed from its socket in the bell crank, but when it is inserted and the lock 0 turned to the position shown in Fig. 3, the grate is released and the lever or handle is locked in position by the engagement of the projection 0, in the recess m. The handle cannot be removed until the lock is again turned to the position indicated in Fig. 2 and consequently it is impossible to remove the operating handle and leave the grate in an incorrect position, and it is equally impossible for the grate to be accidentally shifted or moved while the handle is removed, as, for instance, by the engagement of a bar or implement with either the grate sections or the rocker bars during the cleaning of the fire or the removal of the ashes.

From Figs. 1 and 2 it will be seen that the axis for each set of grate sections and the rocker bar on which they are mounted is located at approximately the center of the sections, while the sockets in the sections and the body portion of the rocker bar that enters said socket are both located at-one side of said axis. With this construction all of the advantages incident to the symmetrical arrangement of the faces of the grate sections about their axis are retained and at the same time the metal of the bar engaging portions of the sections and of the body portions of the rocker bars is so disposed that the least possible obstruction to the flow of air occurs, and the greatest strength is provided with the use of the least weight of metal. The normal angle 7 of the body portion of the rocker bar is and the points of the sections will be caused to penetrate deeply and effectively into the ti'ons against oscillations and for preventing the removal of the handle when the grate sections are out of normal position, consisting of a latch operative independently of the handle, pivotally mounted on the bell crank, a support for said bell crank having a recess whose walls cooperate with said latch, and a projection on the latch extending into the recess in the handle when the latch is out of engagement with the Walls of the recess, whereby the handle is secured to the bell crank, substantially as described.

2. In a shaking grate for furnaces, the combination with the'oscillatory grate sections of substantially equilateral cross section, pivoted bell crank lever connected with said grate sections, a locking latch pivoted on the bell crank above the axis, a'support for the bell crank having a recess in which said latch engages when the grate sections are in normal position to lock the bell crank, a handle mounted removably'in the bell crank lever by which movement is imparted to the bell crank, said handle having a recess with which the latch engages when the grate sections are out of normal position preventing withdrawal of the handle.

3. In a furnace grate, the combination with the oscillatory grate sections, a rocker bar connected to said sections an arm pivotally connected to said bar having a series of equally spaced openings therein, a link having a series of equally spaced openings at its inner end, the distance between centers of the holes in the two members being diflerent and means for securing the members together through holes brought into registry.

JOHN W. F. MACDONALD.

Witnesses:

H. V. BRADY, D. W. COBB, Jr.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner'of Patents,

Washington, D. G. 

